Port Mansfield, TX Frost Dates & Growing Season

The two dates every Port Mansfield garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Jan 12
~50% chance of frost after
First fall frost
Jan 1
~50% chance of frost before
Growing season
354 days
frost-free stretch
USDA zone
≈ 9b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Dec 15 Jan 12 Feb 19
First fall frost Feb 5 Jan 1 Dec 5
Hard freeze (28°F), median last Jan 7 · first Jan 5

Computed from NOAA 1991–2020 climate normals at the PORT MANSFIELD station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for Port Mansfield

Computed from Port Mansfield's own frost dates. Click any crop for the full zone-9 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Nov 17 – Dec 1 Jan 19 – Jan 26
🫑 Peppers Nov 3 – Nov 17 Jan 26 – Feb 2
🥬 Lettuce Dec 1 – Dec 15 Dec 15 – Dec 29 Dec 15 – Jan 12
🫛 Peas Dec 1 – Dec 15
🥕 Carrots Dec 22 – Jan 12
🥦 Broccoli Nov 24 – Dec 8 Dec 22 – Jan 5
🥬 Kale Dec 1 – Dec 15 Dec 15 – Dec 29 Dec 15 – Dec 29
🥒 Cucumbers Dec 15 – Dec 22 Jan 19 – Jan 26 Jan 19 – Jan 26
🥒 Zucchini Dec 15 – Dec 22 Jan 19 – Jan 26 Jan 19 – Jan 26
🫘 Green Beans (Bush) Jan 19 – Jan 26
🌽 Sweet Corn Jan 19 – Jan 26
🌿 Basil Dec 1 – Dec 15 Jan 19 – Jan 26 Jan 26 – Feb 2
🧄 Garlic Fall: Nov 20 – Dec 18

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use Port Mansfield's dates automatically after a lookup.

Reading the season in Port Mansfield

With roughly 354 frost-free days, Port Mansfield gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Jan 1 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Port Mansfield, TX?

The average last spring frost in Port Mansfield is around Jan 12, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in Port Mansfield, TX?

The average first fall frost in Port Mansfield arrives around Jan 1. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in Port Mansfield?

About 354 frost-free days on average, from Jan 12 to Jan 1. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Port Mansfield in?

USDA zone 9b on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.